Plural series motor starting system



Nov. 14, 1950 J. w. WOOLF PLURAL SERIES MOTOR STARTING SYSTEM Original Filed Aug. 16, 1946 a T W 46 lmllmlw MIMI Patented Nov. 14, 1950 PLURAL SERIES MOTOR STARTING SYSTEM James W. Woolf, Franklin, Pa., assignor to Joy Manufacturing Company,

Pennsylvania a corporation of Original application August 16, 1946, Serial No.

690,856. Divided and this application Decemher 8, 1947, Serial No. 790,425

11 Claims. (Cl. 31858) This invention relates to plural series motor starting systems, and more particularly to a starting circuit that first places the motors in series A further object is the provision of a dual eleC- tric motor starting circuit which places themotors in series and then, after a predetermined time delay, places them in parallel.

Other objects and advantages will appear in the course of the specification and in the appended claims.

In the accompanying drawing, in which one illustrative embodiment of my invention is shown:

The figure is a diagrammatic view of the motors, controls and circuits of the illustrative embodiment.

Referring now to the drawing, it will be observed that two motors, respectively designated 4A and 4B, are shown. These motors may drive any suitable apparatus, and, as above indicated, may desirably be used todrive the traction-mechanism. of a vehicle. Each of the motors is a series motor, D. 0., and, in the illustrative embodiment of the invention, may be battery driven, though it will be obvious that the source of electric current is not limited to a battery.- The motors may be driven in series or in parallel, as will later be described. Associated with the motors when these are employed for vehicle propulsion are headlights, identified as F. H. and R. and with these headlights there is associated a-control mechanism including a so-called Safe-off device, thissafe-off and front and rear headlight control device being generally designated I. There is also provided a forward and reverse selective switch mechanism, II, and a fast-slow and reset mechanism, III, these several mechanisms being described in detail as the specification proceeds, and being provided with appropriate operating mechanism not illustrated.

The motors 4A and 4B are, as above noted,

ing, an armature, and a series'field. Each is reversible by forward and reverse contactors. The direction of motor rotation is controlled by the forward and reverse selective switch mechanism II controlled by any suitable operating mechanism, as for example, a handle (not shown) by means of which it may be turned or moved in either of opposite'directions. I

The fast-slow and reset mechanism III causes the motors always to be started in series, irrespective of the operator control of the fastslow and reset mechanism, as later described. This fast-slow and reset mechanism has operating means, not shown, which normally maintains it in an initial or reset position, and which may move it to a part-way forward position in which it establshes series relation between the two motors, and an all-the-way forward position in which the two motors are connected to the source of current in parallel. The operating mechanism for the fast-slow and reset mechanism may, as disclosed in application Ser. No. 690,856, filed August 16, 1946, of which this application is a division, include a control element normally held by a spring in the reset position and movable against the action of the spring successivelyinto the other two positions. The safe-off and front and rear headlight control device I is a safety switch mechanism which requires operation before the other control devices, though operated, can effect any results, and this safe-off and front and rear headlight control device requires one or the other headlight to be on before the vehicle can be setin motion.

As will later be seen, one of the motors is always operated when either is running, and when a series switch S, later more fully described, is closed, motors 4A and 43 will be connected in series across the lines from the current source. One motor will then be very briefly shorted out while the other is connected across the battery,

and the series switch will then be opened and a nected by a conductor I 6 to the coil ll of an overload relay 18. The other end of coil [1 is connected to a conductor l9. A conductor 20 connects the conductor IS with the reversing system of motor 413, while a conductor 2i connects the conductor [9 with one side of a parallel relay or switch P-I, of which the other side is connected to a conductor 22, from which branches 23 and 24 lead respectively to the reversing system of motor 4A and to one side of the series relay or switch S, of which the other side is connected by a conductor 25 to conductors 26 and 21, the first of which is connected with the series field 28 of motor 43, while the second leads to another or second parallel relay or switch, P-Z, whose opposite side is connected by a conductor 29 with a conductor 30 connected with the series field 3| of motor 4A, and with a conductor 32 connected to one side of the other half of the main line switch, and the opposite side of this half of the main line switch is connected by a suitably fused connection 33 with the negative end of the battery.

The reversing system proper of the motors 4A and 4B are the same, and so the system associated with motor 4B needs only to be described. Conductor 20 is connected by conductors 4| and 42 to switch contacts 43 and 44 respectively. A contact 45, connectible by a switch element with the contact 43, is connected by conductor 46 with the commutating winding 41 of motor 4B, and through such winding to the armature 48, through an appropriate brush arrangement. The other brush arrangement is connected by a conductor 49 to conductor 50 leading to a contact 5| opposite contact 44, and by a conductor 52 leading to a contact 53, whose associated contact 54 is connected by a conductor 55 with the series field 28. From the conductor 46 there branches a conductor 56 leading to a contact 51, whose associated contact 58 is connected by a conductor 59 also to the series field 28. Contact members 6| and 62, moved concurrently by a relay means or solenoid 63, are adapted to connect contact '43 with contact and contact 53 with contact 54, when the solenoid is energized, as later explained. Contact members 64 and 65, moved concurrently by a second relay means or solenoid 66, are adapted to connect, when moved to closed positions, the contact 44 with the contact 5| and the contact 58 with the contact 51. There is an interlock, later more fully described, associated with each of the switch devices just described, but not with the corresponding switches associated with motor 4A. These interlocks, which are of the normally open, time delay closing type, are shown for simplicity as actuated by the same armatures that actuate the contact members 6| and 62, and the contact members 64 and 65, but in fact are actuated by the flux of the solenoids, but through delayed action elements of a well known commercial design. The facts that they are not directly actuated by the same armatures and that their actuation is accomplished only after a slight time delay, are indicated by the letters TD.

When the main line switch and the contact members 6| and 62 are closed, the motor 43 is driven in one direction by current passing from the conductor 20 through conductor 4|, switch 43, 6|, 45, conductor 46, commutating winding 41, motor armature 48, conductors 49 and 52, switch 53, 62, 54, conductor 55, series field 28, and the conductor 26, etc. When the contact members 64 and 65 are closed, the motor is driven in the opposite direction by current passing from conductor 20 to conductor 26, as follows: via conductor 42, switch 44, 64, 5|, conductors and 49, motor armature 48, commutating windings 41, conductor 56, switch 51 65, 58, conductor 59 and the series field 28.

The safe-off, front light or rear light device I or 10 may now be considered. This device is controlled by any suitable handle, not shown, and is diagrammatically illustrated as comprising three contact elements 1|, 12 and 13, all movable together, and movable in one direction or the other from a central off position. A suitably fused line 14 leads from the positive line I2 to, and is suitably permanently connected to, the contact element 1|. Contacts 15 and 16 are selectively engageable by contact element 1| as it is moved in opposite directions from its central position. These are connected together as at 11. Both are connected through a conductor r 18 with a relay switch 19 controlled by the overload coil I 1, and thence by a conductor to the fast-slow-reset device I00 later described. Contact 16 is connected by a branching conductor 82 to the front headlight FH and to the rear headlight RH, and the other sides of the front and rear headlights are respectively connected to the contacts 12 and 13 by conductors 83 and 34. Stationary contacts 85 and 86, respectively engageable by the movable contacts 12 and 13 are connected by conductors 81 and 88, and a common conductor 89, with a line 90, which is connected to the negative side of the battery II by way of a fuse 9| and a portion of the conductor 33. From the foregoing description, it will be clear that either headlight may be turned on, dependent on the direction of movement of the device 10, and it will further be noted that there is a branch 92 oil the line 80 which connects with one side of an interlock switch mechanism 93 associated with the main line switch M and which is closed when the main line switch closes, and which when closed establishes a holding circuit for the main line switch through a conductor 94 leading to the negative conductor 90. Moreover, when interlock switch 93 is closed, current is supplied to the fast-slow-reset mechanism as later noted, but attention may now be called, in passing, to the conductor I08.

The fast-slow-reset mechanism is generally designated I 00 or III, as noted above, and it may well be operated by a foot lever not shown where this control is employed on a mine vehicle. This mechanism includes a reset arrangement, an arrangement for effecting connection of the motors in series, and an arrangement for effecting their connection in parallel. These are diagrammatically illustrated at IOI, I02 and I03. While any suitable arrangement may be used in practice, the device |0I is shown as comprising a contact I02 to which the positive line 60 leads, a contact I03 connected to a contact element I01 by a conductor I04, and a movable contact I05 which-connects the contacts I02 and I03 when the three devices IOI, I02 and I03 are in Reset position. The contact I01 of the device I00 is connected by a conductor I08 to the lower end of the main line switch solenoid I09, at a point nearer the latter than the interlock 93. Contact I 01 is adapted to engage a stationary contact I I0, and when so engaged to effect closure of the switch S and connection of the motors 4B and 4A in series to the battery II. Movable contact III of device I03 is adapted to cooperate with a stationary contact I I2 when the operating element is in full forward position and thereby to effect, as later described, connection of the motors in parallel to the battery. The contacts I05, I01 and II I are movable together, but not,

aside from the connection iIOII', electrically con.- nected with each other.

Before describing further, the functions of the device I00, forward and reverse selectivev switch mechanism I (or II). may well be described. This includes three contact elements I2I, and I23, all electrically connected, and all movable together, and havinga neutral. position as shown, and selectively oppositely movable by an operating handle, not shown, to efiect selective forward or reverse drive. Contact I2I. connects with one or the other of connected contacts I and I26 in the difierentturnedpositions of the device I20. It is connectedby a conductor-I28 with contact IIO. When device I20 is moved in one direction, contact I22 contacts a stationary contact I30, and when device I20 is turned in the opposite direction, the contact I23 contacts a stationary contact I3I.

Contact I3I is connected bya conductor I32 having branches I33 and'I34. tothe solenoids 66 and 66, and these solenoids are connected byconductors I36andcI'35 to the line 90. Hence, when contact I23. is in engagement with contact I3I and current is delivered" to contact I I0, the motors will turn in one direction. Contact I is connectedby a conductor- I31. and branchconductors I38 and I39 to the solenoids 63 and 63' and the other ends of thesesolenoids are connected respectively by conductorsI40 and MI to the line 90. Thus when contact I22 and contact I30 are in contact and, current is being delivered to contact IIO, the motors will both turn in the other direction.

It has beennoted that time delay action de- 1 vices, which may now be noted to be numbered I5I, I52, are associated with the reverse switch mechanisms of motor 4B,.and that in whichever direction this motor is connected to run one of these devices I5I or 152 will. be closed. Their closure provides, whencurrent is: being supplied to contact IIO', for. current to. be supplied to contact III a second or so. after the running connections for the motors are established. This, for example, because current. from II10 (when contacted by I01) will flow. via conductor I28, contact I2I, say contact I22, contact. I30, conductors I31 and I38, the conductor I53, switch device I5I, conductor I and conductor I56 to contact element III, and thence may flow to line I58 when contact II I engages contact IIZ. Line I58 connects by a branch I 62 to a normally closedswitch I63 movable with and opened by switch S when the latter is closed, the other side of switch I63 being connectedfiby a 'conductor I 64 to the operating coil I65 of the switch P2", and the opposite end of' this coil is connected by a conductor I66 to the line 90'. Anotherv branch I61 of line I58goes to the operating coil I68 of the switch PI, and the other side of this coil I68 is connected by a conductor 169 back to the line 90. Switch P=I 'hasa switch I '1I movable with it, normally closed, but opened when switch P-I is closed, and controlling current flow to the operating coil of. the switch S. When contact I2I engages either I25 or I26 and current is being conducted to contact I2I current will flow by Way of conductor I13 and switch I1I, through the same when closed, through a conductor I14 to the operating coil or solenoid I12 to close switch S, and then toaconductor 90 by way of a conductor I'1'5. When switch P--I closes switch S will be noted to. open. It may be observed that when the timev delay device I52 is closed, contact I'3'I' will be connected by. conductors I132 and;I34-, a conductor I580;'the time delay switch 152, and conductor I56 to contact III.

The further mode/of operation may now be noted. When the device I00 is turned or moved to the 'right in the drawing, contacts I02 and I03will be moved withv contact I05, and if the solenoid I09is, for any reason, deenergized, as,

by-an overload taking place, resetting by return of contact: I00 to the position shown will be necessary for reclosure of. the main line switch.

Now, assuming that the device I20 has been set to predetermine the direction of motor .operation, movement to the right of switch ele-. ment I01 into contact with contact IIO will'bring about closure of the selected direction-controlling switches and. closure of the switch S, and the motors will be connected in series across the battery. in a manner which will be obvious from what has been said, the current passing through motor 48, through conductors 26, 25, switch S, conductors 24, 23, and motor 4A in series. When device I00 is turned further to the right. and switch element III establishes contact with contact II2, the line I158 will be energized, and the solenoid I68 of switclrP-SI will be energized, andthat switch will be closed, shorting out motor 43 very briefly, and then, because closure of switch PI opens the circuit through thesolenoid I12 of switch S, the latter will open, terminating the short eircuiting of motor 4B; and, as switch S opens, it will, through. the movement of switch I63, close. the circuit through which the solenoid I65 of switch P2 will be energized, and motor 43 will be placed in parallel with motor 4A across the battery, motor 4A having been connected across the battery when switch P-I closed.

The mode of operation of. the control mechanism willv be clear from what has been .said, and it appears iunnecessary'to repeat the details of circuits establishedduring the operations mentioned. It may be observed, however, that because the current to conductor I58 is controlled by one or the other of, switches I5'I, I52, the motor direction control efiecting actions must be completed before the devices operated by the current from conductor I58 can be energized.

Desirably, a. mechanical interlock may be provided between switches P2 and S absolutely to insure against both being closed at the same time, with PI also closed through sticking of the parts or any mechanical difliculty. Such an interlock may be pro-vided in the form of a pivoted lever connected with the movable switch parts of switches S and P2 so that each may be closed separately, but not both together. Such an interlock is shown diagrammatically. at I84. It will be understood by those skilled in the art that the contact I63 of switch S will be provided with a lost-motion device to permit.

closing of switch P2 without interference becauseof the fact that contact I63 is already in its extreme lower position. Such interlocks and. lost-motion devices are well known in the art and need, not be detailed here.

The various controls, especially the mechanisms 10, I00, I20, andswitch devices I5I and I52, .are shown very much in diagrammatic form, for simplicity of illustration, and itwill of course be understood that arrangement for making movableparts stationary and vice versa are all within the scope of my invention to the extent coveredby the appended claims.

From what has been said, it will be appre-;

ciated that this invention provides a very useful and desirably functioning motor control system having adaptability to other uses, but operative very effectively in the propulsion of mine vehi cles. The controls are very simple, effective, guard against harmful results of oversight, and though the operator might inadvertently or even deliberately attempt to start the motors in parallel through immediate movement of the fastslow-reset device to the limit of its extreme operating position, yet the motors would still be started in series though they would relatively quickly pass through the series connection stage and be in parallel across the battery.

While there is in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the invention is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a dual motor circuit comprising relay means having contacts in separate circuits connected to each motor, a series relay having a contact to connect said motors in series when energized, a parallel relay for connecting one side of said motors together, a connection to energize the series relay through a normally closed contact of said parallel relay, a normally open time delay closing contact energized with the operation of said relay means to close a circuit and energize said parallel relay which opens the circuit of said series relay, a normally closed contact actuated by said series rela to connect a circuit to a second parallel relay which connects together the other side of said motors to complete the circuit placing them in parallel.

2. In a dual motor circuit comprising relay means having contacts in separate circuits connected to each motor, a series relay having a contact to connect said motors in series when energized, a parallel relay for connecting one side of said motors together, a connection to energize the series relay through a normally closed contact of said parallel relay, a normally open time delay closing contact energized with the operation of said relay means to close a circuit and energize said parallel relay which opens the circuit of said series relay, a second parallel relay having a mechanical interlock with said series relay and energized by said normally open time delay closing contact for connecting the other side of said motors together.

:3. In the motor circuit of claim 1, switch means for energizing said relay means and said series relay to operate said motors in series.

4. In the motor circuit of claim 2, switch means for energizing said relay means and said series relay to operate said motors in series.

5. In a motor circuit according to claim 1, switch means for energizing said relay means and said series relay to operate said motors in series at least as long as the period required to operate said time delay contact.

6. In a motor circuit according to claim 1, a two position switch means connected in its first position to energize said relay means and said series relay to operate the motors in series and connected in its second position to maintain energization of said relay means and to close the control circuit to both of said parallel relays, said motors operating in series at least as long as the period required to operate the time delay contact.

7. A motor circuit according to claim 1, characterized in that the contacts of said relay means are in each of two opposite legs of respective four-legged bridge reversing motor circuits.

8. In a dual motor running and reversing circuit, the combination of two motors each having forward and reverse relay means and each relay means provided with a contact in each of two opposite legs of a respective four-legged bridge reversing circuit for each of said motors, a series relay having a contact to connect said motors in series when energized, a parallel relay for connecting one side of said motors together, a connection to energize the series relay through a normally closed contact of said parallel relay, a normally open time delay closing contact energized with the operation of said relay means to close a circuit and energize said parallel relay which opens the circuit of said series relay, a normally closed contact actuated by said series relay to connect a circuit to a second parallel relay which connects together the other side of said motors to complete the circuit placing them in parallel.

9. In a motor circuit according to claim 8, twoposition switch means connected when actuated to the first position to selectively operate said motors in series for forward or reverse operation and when actuated to the second position to selectively operate the motors in parallel for forward or reverse operation, the parallel operation of said motors requiring a series connection of said motors for at least the duration of the operation of said time delay closing contact.

10. In a motor circuit according to claim 8, means to selectively energize the forward or reverse relay means to operate the motors in series or parallel, the parallel operation of said motors requiring a series connection of said motors for at least the duration of the operation of the time delay closing contact.

11. In a dual motor running and reversing circuit, the combination of two motors each having forward and reverse relay means and each relay means provided with a contact in each of two opposite legs of a respective four-legged bridge reversing circuit for each of said motors, a series relay having a contact to connect said motors in series when energized, a parallel relay for connecting one side of said motors together, a connection to energize the series relay through a normally closed contact of said parallel relay, a normally open time delay closing contact energized with the operation of said relay means to close a circuit and energize said parallel relay which opens the circuit of said series relay, a second parallel relay having a mechanical interlock with said series relay and energized by said normally open time delay closing contact for connecting the other side of said motors together.

JAMES W. WOOLF. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 801,214 Case Oct. 10, 1905 932,114 Folsom Aug. 24, 1909 1,037,433 Carichoff Sept. 3, 1912 2,348,053 BoWker May 2, 1944 2,371,555 Stamm Mar. 13, 1945 

